Design and Implementation of Three-Layer Mesoporous Silica Coating for Tri-wavelength Broadband Antireflection by Block Copolymer Assisted Sol-Gel Method

A three-layer tri-wavelength broadband antireflective (AR) coating has been successfully fabricated on quartz substrate via a sol-gel route using acid-catalyzed silica sols. An ethylene oxide-propylene oxide-ethylene oxide triblock copolymer is used as a template to prepare ordered mesoporous SiO2 films. Assisted by Filmstar thin film design software, film thickness for each layer is optimized based on actual optical constants of the three mesoporous silica films. The three layers generate a reasonable refractive index gradient from the air, and thus the obtained AR coating possesses high transmittance of 99.24%, 99.66%, and 99.64% at 351 nm, 527 nm, and 1053 nm, respectively. The mesoporous SiO2 films with tough skeletons despite different porosity endow the coating with good abrasion-resistance, and 1H, 1H, 2H, 2H-Perfluorodecyltriethoxysilane is further used to modify the surface of the AR coating, which can improve the experimental stability of the coating. This work provides beneficial references for AR coating production of the sol-gel technique.

Automated summary

A three-layer tri-wavelength broadband antireflective (AR) coating was successfully fabricated on a quartz substrate using acid-catalyzed silica sols via a sol-gel route. Ordered mesoporous SiO2 films were prepared using an ethylene oxide-propylene oxide-ethylene oxide triblock copolymer as a template. The film thickness for each layer was optimized based on the actual optical constants of the three mesoporous silica films using Filmstar thin film design software. The resulting AR coating exhibited high transmittance at 351 nm, 527 nm, and 1053 nm, with values of 99.24%, 99.66%, and 99.64%, respectively. The mesoporous SiO2 films with tough skeletons and different porosity provided good abrasion resistance to the coating. Additionally, the surface of the AR coating was modified using 1H, 1H, 2H, 2H-Perfluorodecyltriethoxysilane to improve its experimental stability. This work provides valuable references for the production of AR coatings using the sol-gel technique.